/*
Open Asset Import Library (assimp)
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*/

/** @file Md3FileData.h
 *
 *  @brief Defines helper data structures for importing MD3 files.
 *  http://linux.ucla.edu/~phaethon/q3/formats/md3format.html
 */
#ifndef AI_MD3FILEHELPER_H_INC
#define AI_MD3FILEHELPER_H_INC

#include <string>
#include <vector>
#include <sstream>

#include "../include/assimp/types.h"
#include "../include/assimp/mesh.h"
#include "../include/assimp/anim.h"

#include "./../include/assimp/Compiler/pushpack1.h"

namespace Assimp	{
namespace MD3	{

// to make it easier for us, we test the magic word against both "endianesses"
#define AI_MD3_MAGIC_NUMBER_BE	AI_MAKE_MAGIC("IDP3")
#define AI_MD3_MAGIC_NUMBER_LE	AI_MAKE_MAGIC("3PDI")

// common limitations
#define AI_MD3_VERSION			15
#define AI_MD3_MAXQPATH			64
#define AI_MD3_MAXFRAME			16
#define AI_MD3_MAX_FRAMES		1024
#define AI_MD3_MAX_TAGS			16
#define AI_MD3_MAX_SURFACES		32
#define AI_MD3_MAX_SHADERS		256	
#define AI_MD3_MAX_VERTS		4096	
#define AI_MD3_MAX_TRIANGLES	8192	

// master scale factor for all vertices in a MD3 model
#define AI_MD3_XYZ_SCALE		(1.0f/64.0f)

// -------------------------------------------------------------------------------
/** @brief Data structure for the MD3 main header
 */
struct Header
{
	//! magic number
	uint32_t IDENT;

	//! file format version
	uint32_t VERSION;

	//! original name in .pak archive
	char NAME[ AI_MD3_MAXQPATH ];

	//! unknown
	int32_t FLAGS;

	//! number of frames in the file
	uint32_t NUM_FRAMES;

	//! number of tags in the file
	uint32_t NUM_TAGS;

	//! number of surfaces in the file
	uint32_t NUM_SURFACES;

	//! number of skins in the file
	uint32_t NUM_SKINS;

	//! offset of the first frame
	uint32_t OFS_FRAMES;

	//! offset of the first tag
	uint32_t OFS_TAGS;

	//! offset of the first surface
	uint32_t OFS_SURFACES;

	//! end of file
	uint32_t OFS_EOF;
} PACK_STRUCT;


// -------------------------------------------------------------------------------
/** @brief Data structure for the frame header
 */
struct Frame
{
	//! minimum bounds
	aiVector3D min;

	//! maximum bounds
	aiVector3D max;

	//! local origin for this frame
	aiVector3D origin;

	//! radius of bounding sphere
	float radius;

	//! name of frame
	char name[ AI_MD3_MAXFRAME ];

} PACK_STRUCT;


// -------------------------------------------------------------------------------
/** @brief Data structure for the tag header
 */
struct Tag
{
	//! name of the tag
	char NAME[ AI_MD3_MAXQPATH ];

	//! Local tag origin and orientation
	aiVector3D  origin;
	float  orientation[3][3];

} PACK_STRUCT;


// -------------------------------------------------------------------------------
/** @brief Data structure for the surface header
 */
struct Surface
{
	//! magic number
	int32_t IDENT;

	//! original name of the surface
	char NAME[ AI_MD3_MAXQPATH ];

	//! unknown
	int32_t FLAGS;

	//! number of frames in the surface
	uint32_t NUM_FRAMES;

	//! number of shaders in the surface
	uint32_t NUM_SHADER;

	//! number of vertices in the surface
	uint32_t NUM_VERTICES;

	//! number of triangles in the surface
	uint32_t NUM_TRIANGLES;


	//! offset to the triangle data 
	uint32_t OFS_TRIANGLES;

	//! offset to the shader data
	uint32_t OFS_SHADERS;

	//! offset to the texture coordinate data
	uint32_t OFS_ST;

	//! offset to the vertex/normal data
	uint32_t OFS_XYZNORMAL;

	//! offset to the end of the Surface object
	int32_t OFS_END;
} PACK_STRUCT;

// -------------------------------------------------------------------------------
/** @brief Data structure for a shader defined in there
 */
struct Shader
{
	//! filename of the shader
	char NAME[ AI_MD3_MAXQPATH ];

	//! index of the shader
	uint32_t SHADER_INDEX;
} PACK_STRUCT;


// -------------------------------------------------------------------------------
/** @brief Data structure for a triangle
 */
struct Triangle
{
	//! triangle indices
	uint32_t INDEXES[3];
} PACK_STRUCT;


// -------------------------------------------------------------------------------
/** @brief Data structure for an UV coord
 */
struct TexCoord
{
	//! UV coordinates
	float U,V;
} PACK_STRUCT;


// -------------------------------------------------------------------------------
/** @brief Data structure for a vertex
 */
struct Vertex
{
	//! X/Y/Z coordinates
	int16_t X,Y,Z;

	//! encoded normal vector
	uint16_t  NORMAL;
} PACK_STRUCT;

#include "./../include/assimp/Compiler/poppack1.h"

// -------------------------------------------------------------------------------
/**	@brief Unpack a Q3 16 bit vector to its full float3 representation
 *
 *	@param p_iNormal Input normal vector in latitude/longitude form
 *	@param p_afOut Pointer to an array of three floats to receive the result
 *
 *	@note This has been taken from q3 source (misc_model.c)
 */
inline void LatLngNormalToVec3(uint16_t p_iNormal, float* p_afOut)
{
	float lat = (float)(( p_iNormal >> 8u ) & 0xff);
	float lng = (float)(( p_iNormal & 0xff ));
	lat *= 3.141926f/128.0f;
	lng *= 3.141926f/128.0f;

	p_afOut[0] = cosf(lat) * sinf(lng);
	p_afOut[1] = sinf(lat) * sinf(lng);
	p_afOut[2] = cosf(lng);
	return;
}


// -------------------------------------------------------------------------------
/**	@brief Pack a Q3 normal into 16bit latitute/longitude representation
 *	@param p_vIn Input vector
 *	@param p_iOut Output normal
 *
 *	@note This has been taken from q3 source (mathlib.c)
 */
inline void Vec3NormalToLatLng( const aiVector3D& p_vIn, uint16_t& p_iOut ) 
{
	// check for singularities
	if ( 0.0f == p_vIn[0] && 0.0f == p_vIn[1] ) 
	{
		if ( p_vIn[2] > 0.0f ) 
		{
			((unsigned char*)&p_iOut)[0] = 0;
			((unsigned char*)&p_iOut)[1] = 0;		// lat = 0, long = 0
		} 
		else 
		{
			((unsigned char*)&p_iOut)[0] = 128;
			((unsigned char*)&p_iOut)[1] = 0;		// lat = 0, long = 128
		}
	} 
	else 
	{
		int	a, b;

		a = int(57.2957795f * ( atan2f( p_vIn[1], p_vIn[0] ) ) * (255.0f / 360.0f ));
		a &= 0xff;

		b = int(57.2957795f * ( acosf( p_vIn[2] ) ) * ( 255.0f / 360.0f ));
		b &= 0xff;

		((unsigned char*)&p_iOut)[0] = b;	// longitude
		((unsigned char*)&p_iOut)[1] = a;	// lattitude
	}
}

}
}

#endif // !! AI_MD3FILEHELPER_H_INC

